1. Technical Field
The present invention relates to an aqueous ink composition, an ink jet recording method, and recorded matter produced by the ink jet recording method using the aqueous ink composition.
2. Related Art
Non-aqueous ink compositions containing organic solvent are quick to dry and cause little bleeding or blurring and have therefore been used in recording on nonabsorbing media, such as plastics, that do not absorb ink. From the standpoints of global environment protection and safety, however, aqueous ink compositions containing water as solvent are becoming widespread.
Some aqueous ink compositions containing a yellow pigment as a coloring material contain C.I. pigment yellow 74 as the yellow pigment. However, C.I. pigment yellow 74 has insufficient light resistance. Thus, C.I. pigment yellow 180 is being studied to improve light resistance.
However, aqueous ink compositions containing C.I. pigment yellow 180 may have low storage stability at low temperature. More specifically, thawing of aqueous ink compositions containing C.I. pigment yellow 180 in a frozen state stored at a low temperature of −10° C. or less can cause the agglomeration of the pigment. For example, in JP-A-2005-60411, JP-A-2005-60419, and JP-A-2007-154087, a moisturizing component, such as glycerin, is added to aqueous ink compositions containing a yellow pigment to prevent the freezing of the aqueous ink compositions. The addition of a moisturizing component, such as glycerin, to aqueous ink compositions containing a yellow pigment sometimes improves low-temperature storage stability.
The formation of images on recording media, such as plastics, using aqueous ink compositions containing a yellow pigment may cause blurring of the images by contact with another color pigment, thereby producing low-quality images. In order to avoid this problem, it is known that an alkanediol is added to an aqueous ink composition to reduce blurring of images.
For example, JP-A-2007-154087 discloses that the addition of 1,2-hexanediol to an aqueous ink composition can produce high-quality images without chrominance non-uniformity in some recorded images.
However, the addition of a moisturizing component, such as glycerin, to aqueous ink compositions containing C.I. pigment yellow 180 has sometimes reduced the abrasion resistance of images formed on recording media, such as plastics, thereby producing low-quality images.
Furthermore, the addition of an alkanediol to aqueous ink compositions containing C.I. pigment yellow 180 has sometimes reduced the low-temperature storage stability of the aqueous ink compositions.